- The world's population reached its first billion in 1800
- It then took 123 years to reach its seconds billion in 1933
- The rate of growth then almost quadrupled, reaching the third billion just 33 years later.
- The transitions between the 4th, 5th and 6th billions were both 12 years, indicating a slowing in population growth.
- It is predicted that the population will reach 9 billion in 2054, 23 years after reaching the 8th billion
Contribution to population growth
Although the population has grown exponentially, MEDCs have made very little contribution to this. LEDCs are mainly accountable for the dramatic changes seen in population trends throughout history.
Analysts disagree on the future of population growth.
- The most pessimistic viewpoint suggests that the population will reach 14 billion by 2100 and continue to grow past this figure.
- Another suggests that growth will plateau at 9 billion by 2075
- The most optimistic theory suggests that population will peak at 7.5 billion by 1934 and begin to fall thereafter.
The Demographic Transition Model
- Stage 1: High Fluctuating (Ethiopia, Bangladesh and Rainforest tribes)
- Stage 2: Early Expanding (Sri Lanka, Kenya)
- Stage 3: Late Expanding (China, Cub, Australia)
- Stage 4: Low Fluctuating (UK, Japan, Canada)
- Stage 5: Fluctuating/Declining (Hungary)
UK's movement through the demographic transition m
- The UK was in stage 1 of the DMT until 1740.
- 1665: Great Plague
- 1720 - 1740: Cheap Gin available damaged people's health (Gin tax introduced in 1751)
- The UK was in stage 2 of the DMT between 1740 and 1850
- 1770-1870: infant mortality reduced because if improved sanitation
- 1780: improved agriculture
- 1798: Small pox vaccine
- 1800: Industrial revolution (people moved to cities and employers demanded food for their workers)
- 1848: Public health act reduced TB and scarlet fever
- The UK was in stage 3 of the DMT between 1850 and 1940
- Child labour was harder to find
- Late 19th century, sewage was managed and water supplies cleaned
- 1910: improved health of mothers and infants
- The UK is currently in stage four of the DMT
- 1950: Post war baby boom
- 1960: Oral contraceptives introduced
- 1967: Abortions legalised
Evaluation of the DMT: Limitations
- Doesn't consider global transfer of medical and technological knowledge: less developed countries will develop more quickly. (UK 123 year transition between stages 1 and 2, china 15 year transition)
- Doesn't consider that some LEDCs have higher birth rates than the UK had when in the same stages
- Doesn't consider influences in society such as religion and war.
- It is unlikely that some countries will ever reduce their birth rates to as low as is described in stage 4.
- Doesn't consider migration
- There was originally no stage 5 and there is now a need for a stage 6 and there are no countries to base it on.
- Birth/death rates can vary dramatically within a country
Evaluation of the DMT: Uses
- Can be used to predict approximate changes in population, allowing countries to be prepared for challenges
- Rough trends are applicable to most countries
Population Variation within countries
- Urban environments have very different population structures to rural ones.
- Dar-es-salam (Tanzania's largest city) has a very youthful population, not due to high birth rates but due to migration of young people into city environments. There is a contrastingly low proportion of elderly people.
- Barro (Island in the Outer Hebrides, Scotland) demonstrates rural depopulation. There is a relatively health population of children up to 14, however the proportion of 15 - 19 years olds drops dramatically due to moves to cities for university and careers.
Total Fertility Rate
- World fertility rate trends : Africa has the highest fertility rates, particularly Sub-Saharan Africa, for example Uganda.
- Europe has the lowest fertility rate
- The northern hemisphere countries have lower fertility rates than southern hemisphere countries.
Factors affecting fertility rate
- Urbanisation: Increased consumerism means that people are becoming more interested in material belongings, making children less of a priority. People are also choosing to focus more on their careers, reducing fertility rate.
- Literacy rates: If women have an education, they are less likely to have lots of children as they are educated on birth control and have better career prospects. (Kerala, India: 93% Literacy, 2.3 TFR / Gujurat, India: 59% Literacy, 4.0 TFR)
- Death rates (Infant mortality rate): In some Sub-Saharan countries, women must have 8-9 children in order to be 95% sure that they will have a surviving son.
- Tradition and customs: Islam and Catholicism suggest that birth control should not be used although adherence to religious doctrines reduces with development (eg Italy is a catholic country by has a TFR of just 1.2). In some cultures, women are thought of a soley child bearers and a man's status is based on the number of children he has. In Nigeria, just 4% of women with 2 children said they didn't want another, whereas in Vietnam, 92% of women said they didn't want any more children.
- Government policies (pro or anti natalist) influence family planning decisions. (Japan, France and Russia have had pro-natalist policies in the past and China has an anti-natalist policy (One Child Policy))